The summer of 2015 saw the completion of the Black Hills State University Underground Campus (BHUC) and the CASPAR cavern (Compact Accelerator System for Performing Astrophysical Research) at the Ross Campus. The two projects added nearly 1,425 square feet to Sanford Lab?s underground footprint, increasing the need for industrial water underground.
It was a perfect time to upgrade the current water system that supplies water for drilling, cooling and fire suppression. The new upgrade required that a reservoir be built on the 4100 Level and the installation of roughly 3,000 feet of pipe.
The job fell to Facility Engineer Andrew Brosnahan, who developed the concept for the 4100 reservoir and 4850 Level work. The project involved building a dam in a drift on the 4100 Level that feeds water through a series of pipes down the Yates Shaft and over to the Ross Campus. ?It was a major undertaking by everyone involved,? Brosnahan said.
The reservoir, which increases the capacity for the Ross Campus, is over 500 feet long, with 65-inch walls on both ends and a concrete slab that spans the first 10 feet. An 18-inch middle wall prevents silt from spilling into the industrial water, while pass-through pipes isolate reservoir water from natural mine inflow water. The 100,000-gallon reservoir is filled using clean water from the surface. The reservoir discharge travels down the shaft to the 4850 Level.
A manifold near the Yates 4850 station reduces the water pressure from 320 pounds per square inch (psi) to 80 psi so it can be used by the underground and Ross Campus. From the manifold the water travels through 3,000 feet of 6-inch pipe down the West Drift. The pipe is secured with a series of unistrut hangers that are bolted to the ribs and back of the drift. ?It?s a great upgrade for Sanford Lab,? Brosnahan said. ?The hangers are expandable so they can hold future utilities we may need.?
The project is nearly complete and Brosnahan credits many people for the progress. Mechanical Engineer Mike Johnson worked closely with Brosnahan to develop the 4100 reservoir concept. The Underground Maintenance Crew did the majority of the work on the 4100 cleaning up the drift, running pipe and pouring concrete walls one 5-gallon bucket at a time. Other underground access crews installed rock bolts and pipe on the 4850, installed valves and piping at the dam on the 4100, and lowered pipe down the shaft on the Zimmerman, 15 sections at a time.
?This was a real team effort,? Brosnahan said. ?Everyone did a tremendous job on this and the whole project looks amazing.?